Getter assemblies are well known in the art. They are extensively used in display tubes such as cathode ray tubes. In use the getter assembly is heated to a high temperature, usually by means of high frequency induction heating whereupon a getter metal, usually barium, is caused to evaporate from the getter assembly. The getter assembly, within the cathode ray tube, may be located in the antenna position or fixed to the anode buttom. However, whatever its position it is usually in contact with the inner surface of the glass envelope which forms the cathode ray tube.
Unfortunately the high temperature, 1000.degree. C. or more reached by the getter assembly during evaporation of the getter metal is such as to cause cracking of the glass envelope. It has thus become customary to provide some form of thermal insulation or support between the getter material holder and the glass wall. Ceramic insulators have been used, as described in U.S. Pat. No. 3,381,805 or wire supports, as described in U.S. Pat. No. 4,101,247. Another type of support is described in Japanese utility model application publication No. 50-11453.
Nevertheless such insulating or support means are either expensive or have too high a temperature at the point of contact between the support and the glass envelope.